Russia has been working on Trump for decades, he's an amusing idiot. They manipulated him, people around him, the electorate, and the election to engineer the situation where this fool is in the presidency. They have hard power over him (compromising pictures, information, loans, etc) and soft power over him (he admires strongmen autocrats).

The rise of the alt-right took weaknesses in the right and left and amplified them to engineer the situation where there was a populist takeover of the Republican party. Epstein met moot. 4chan took a turn from being the asshole of the internet that was the original source of the concept of memes and a lot of other internet culture and turned it political and the conspiracies and thought processes jumped from 4chan to your dimwitted fox news loving uncle.

All of this is taking and molding stupidity and weaknesses in order to achieve outcomes: international conflict and weakening America on the world stage with both its allies and adversaries. Not outright commanded by foreigners but shaped by them taking advantages of the post-9/11 fear and general stupidity and anti-intellectualism and fear of immigration.